Propylene Glycol from Chlorine and Propylene

Products

Propylene Glycol. Propylene Glycol (a.k.a. Propane-1,2-diol) is a clear, colorless, non-corrosive, but strongly hygroscopic difunctional alcohol in such a way that it must be protected from exposure to the atmosphere. Unique among the glycols, Propylene Glycol has low toxicity to humans. The largest application of Propylene Glycol is in the production of polyester resins, although it also has a wide application in the food, pharmaceutical, and cosmetic industries. Propylene Glycol also has great solvent properties for several polar organic materials, such as phenols, alcohols, dyes, natural products, and even some resins. Moreover, due to its property of reducing the water freezing point, PG has been used as an option for aircraft deicing and anti-icing fluids. This commodity was first manufactured in 1859 by the hydrolysis of propylene glycol diacetate However, it was only in 1931 that it was first commercialized and used as a substitute for glycerol in pharmaceuticals.

Dichloropropane. This saturated organochloride is mostly used industrially for the manufacture of other chlorinated chemicals, and can also be used as a solvent for certain processes.

Raw Materials

Chlorine. Chlorine figures among the most important chemical commodities. It is an indispensable intermediate in the chemical industry, employed in the manufacture of a multitude of end products (e.g. materials of construction, solvents, pesticides, etc). Most of chlorine produced on commercial scale is based on electrolysis of aqueous sodium chloride (brine), which also generates caustic soda and hydrogen as co-products (chlor-alkali processes).

CG Propylene. Propylene, the main raw material consumed, is a colorless gas at room temperature. It is a low-boiling, flammable, and highly volatile gas. Propylene reacts vigorously with oxidizing materials. The primary hazard associated with propylene is its flammability - precautions must be taken to avoid fire hazards in the handling of the gas. Propylene has been mainly produced as ethylene manufacturing co-product (via steam cracking of paraffinic hydrocarbons) and by-product of petroleum refining (separation from refinery gas). Most recently, amid a tight propylene market, novel lower-cost chemical processes for on-purpose propylene production have emerged.